The program is evaluating the rheological parameters of blood (blood viscosity at various rates of shear, hematocrit, red cell deformability, fluidity and size, degree of cellular aggregation, plasma viscosity and serum protein profile) as diagnostic and prognostic indices for diseases related to or produced by altered blood flow. In addition the degree of correlation between the parameters will be determined in order to establish a minimum set of measurements for a hemorheological profile on blood samples. Patients with diagnosed arteriosclerotic cardiovascular disease or plasma hyperviscosity syndromes as well as women using oral contraceptives will be compared with clinically normal subjects. The designation "normal" for volunteer subjects is being established from the blood chemistry profile and the hematological indices of the blood. Significant elevations over normal values for apparent blood viscosity over a wide range of shear rates at comparable hematocrits have been found for the patients and also for women using oral contraceptives. Precise knowledge of the nature of the interactions between blood viscosity related factors should enable the hemorheological profile to be used for monitoring the course of diseases, improving diagnostic tests and as an aid in devising therapeutic manipulations to produce selective modification of deviant rheological parameters.